so something i am curious about...
is it as easy to use as essentials?
you know with essentials you can make a game without knowing much about scripting...
it wouldn't be that good but its possible...
and aren't there some limitations that you have to consider?
for example the rom size and all the other technical stuff?
can you add every audio format you want to use or do you have to use midi?
you said that you add the maps as png files right?
how do you manage the priority of the tiles or autotiles?
there are more points that i am curious about but i think the above are enough for now...

ahh and i doubt that you can sell any game which use pokemon related stuff...
maybe if you use only fakemon and avoid using anything pokemon related like pokeballs or any sprite used in the official games...
but i dont think that someone would spend money to buy a pokemon lookalike instead of buying the official games...

but i have to say that if you manage to make a DS variant of essentials it would be awesome for any fangame developer! :D

You won't need much scripting knowledge for this. Right now I'm working on automating all events. For example, the door event in the preview was originally 6/7 different event functions on that object. I created my own event function that combined the 6 previous ones so that when you want to create a door, you just select the function 'door' from the menu in the event creator and you provide the following arguments: x coordinate of door, y coordinate of door, teleport location and sound of door. It will be that simple for 90% of the commands.

I don't think room size will be that much of a problem. Read the OP RE how DS Game Maker/PaLib converts the maps to a tileset.

Audio is added using MP3 or WAV files.

Yes, each map will be a .png file. Priority in PokeDS will be much simpler than RMXP, you will not need to use that 1-6 numbering system which I despised with a passion. A picture tells a thousand words. 3 will tell quite a lot:

The first image is the map - quite self explanatory.

The second image is the collision map. Red is walkable area. Any other colour is blocked. Also note the different colours there. Yellow represents a door. The creator of the RPG movement functions (all credit goes to him for these images and functions) coloured these areas so that the game knows which area the player is colliding with. For example, he originally had it so that when he collided with the door, a message would pop up saying "This door is locked". The water is also coloured blue. What I plan on doing is creating special colours for each area on the map. For example water would be coloured blue and water would be recognised to be walkable if the character is currently surfing. We could also add green to the collision map to denote grass areas for wild pokemon encounters. This would give the added benefit over terrain tags in the idea that you can put grass that does not have encounters.
Also note how small the collision map is. This is because it is scaled down to the ratio 1 pixel:1 tile.

The third image is the priority map. Any parts of your map that the main character should appear behind will be part of this map.

All three of these "backgrounds" (as DS Game Maker calls them) can be easily mapped using Tiled. It may seem like a complicated process but in my opinion, it allows for much more rigorous mapping - you can control exactly where collisions can occur and where your priorities are as opposed to applying those properties to just a tileset.

And yeah I realised after posting that Pokemon is copyrighted. The idea is still the same though. This would give people a chance to distribute their games to a much larger audience. And there's always the portability benefit!

If you have any more questions, don't hesitate to ask. I want to get all feedback and ideas from the beginning so I can get everything right from the get go.

Also I'd just like to point out that I did change that ugly door noise that was in the preview. That's the only one I could find.